While it is possible to change a git tag to refer to another commit, I wouldn’t recommend it. In particular, the Julia package manager associates package versions with specific git SHAs. Editing that release would require changing the associated SHA. That would lead to a situation where two users could both have
v0.9.2 but have different code, which breaks the whole notion of version numbers being a meaningful description of the exact code a user has.
On the other hand, it looks like v0.9.3 was never merged into METADATA: https://github.com/JuliaLang/METADATA.jl/pull/11716 , so changing what that tag points to won’t affect the Julia package manager. Why not just make whatever fixes you wanted for 0.9.2, call them v0.9.3 and publish that? You can delete tags directly from github if you don’t want to do it on the command line: https://github.com/JuliaGraphics/Luxor.jl/releases/tag/v0.9.3 and you can create a new github release (which also creates a git tag automatically) pointing to any commit from https://github.com/JuliaGraphics/Luxor.jl/releases (just change the option in the drop-down from
master to whatever commit or branch you’ve pushed your 0.9.3 fixes to).